抄録
Based on recent progress on Cenozoic stratigraphy and molluscan biostratigraphy of the Japanese Islands, the causes and effects of some geological and paleoenvironmental events are discussed in relation to Pacific gateway events. The silica biomarker change that was recognized in Kamchatka at the Eocene/Oligocene transition possibly corresponded to the first cooling event of the Antarctic ice sheet. The drastic change in the same biomarker detected at the Oligocene/Miocene boundary in northern Sakhalin possibly was a response to the upwelling of cold deep water related to the opening of the Drake Passage. It is also considered that the invasion event of the tropical/subtropical bivalve Hataiarca kakehataensis (Hatai and Nisiyama) at 17 Ma in the Japanese Islands might have taken place in response to the closure of the Indonesian seaways. It is important to consider the scenarios of the cause and effect of geological events in response to global events.
